| The problems of energy shortage and environmental pollution have become two major problems faced by all the countries in the world. Facing the serious situation, governments and automobile industry of all the countries are aware that developing the new energy vehicles can alleviate the above two problems in a certain extent in the process of continuous exploration. At present, the hybrid electric vehicle (HEV) is considered one of the major countermeasures and the most realistic choices to deal with the energy and environment problems.As one of the main energy sources of the hybrid electric vehicle, the power battery affects the performance of HEV directly. The main parameter that affect the power battery performance is the temperature, which is also one of the most important parameters that can be controlled by the power supply system. In order to make the power battery to achieve the best performance and service life, and eliminate potential hazards, the temperature should be controlled in a certain range, at the same time, reduce temperature inhomogeneity of the power Li-ion battery pack. So researching on the thermal characteristics of the power battery pack is of great significance. This dissertation gives a research on the power battery pack of a HEV. The characteristic of the temperature increase of the power Li-ion battery and the temperature field simulation are carried out by using the numerical method. The main content of this thesis:(1) Research the development of the HEV and the status of the Li-ion battery and its thermal characteristics.(2) Discuss the structure and working principles of the Li-ion battery in detail. And analyze the thermogenesis mechanism of the power Li-ion battery. It shows that the heat mainly comes from the Joule heat and the electrochemical reaction heat.(3) Analyze the heat transfer methods and the heat transfer processes inside the power battery pack and find the way to study the power battery which is called Computational Fluid Dynamics.(4) Analyze the necessity of the cooling simulation the power Li-ion battery and establish the heat dissipation model. The physical parameters, the heat production rate and other conditions which are used in the thermal field simulation of the power Li-ion battery are determined. And the temperature rise of the power Li-ion battery in different heat production rate are simulated by using Icepak.(5) Use Icepak to build the power battery pack temperature field simulation model and carry out the numerical simulation analysis. And optimize the structure of the power battery pack according to the results of the analysis.(6) Briefly analyze and describe the goals and the basic procedure of the design of the power battery thermal management system. And analyze the cooling and heating systems, and the position the power battery pack should be placed in the vehicle. |
PDF Full Text Request